Tablet feed hoppers



Dec. 18, 1956 ALDRED 2,774,519

TABLET FEED HOPPERS Filed July 51, 1952 2 Sheets-Sheet l Dec. 18, 1956 ALDRED 2,774,519

TABLET FEED HOPPERS Filed July 31; 1952 2 Sheets-Sheet 2 TABLET FEED HOPPERS Leslie Aldred, Blackley, Manchester, England, assignor to Imperial Chemical Industries Limited, a corporation of Great Britain Application July 31, 1952, Serial No. 301,864 Claims priority, application Great Britain August 3, 1951 6 Claims. (Cl. 222---310) This invention relates to tablet feed hoppers and more particularly to means for regulating the How of tablets from the hopper.

Means that have hitherto been proposed for feeding tablets from hoppers include vibration of the hopper and movement across the bottom or side of the hopper of a perforated plate in which the perforations are large enough to take one tablet. These means suffer from the disadvantages of causing damage to the tablets and producing large quantities of dust by wear on the tablets.

It is an object of the present invention to provide a means for regulating the flow of tablets from a hopper that is free from those disadvantages.

According to the invention there is provided a tablet feed hopper having a sloping base and a short outlet passage in the side at the lower end of the sloping base, said outlet passage being partially closed by a brush suspended so that the ends of the bristles are a small distance above the sloping base of the passage and arranged to oscillate across the passage.

The outlet passage from the hopper is conveniently arranged as a continuation of the sloping base, with low side plates to guide the tablets. The opening from the hopper to the passage is large enough to allow tablets to fall out of the hopper much faster than the desired feed rate, which is controlled by the brush at the end of the passage. If desired, the passage may be divided up longitudinally so as to provide two or more streams of tablets from the'one hopper and brush; by a still further modification, separate brushes may be provided for each stream of tablets.

The oscillatorymotion of the brush is preferably such that the bristle motion has both a sideways and a vertical 7 component, that is components both parallel to and normal to the plane of the hopper base. The sideways component serves to agitate the tablets in contact with the brush, while the vertical component allows tablets to fall out of the passage when the bristles rise. The rate of feed of the tablets may be controlled by the frequency or the amplitude of the brush oscillation or by the spacing of the ends of the bristles from the base of the passage. When the passage is divided longitudinally to provide two or more streams of tablets, such streams may be controlled independently by adjusting the distance of the base of each portion of the passage from the ends of the bristles. By a further modification the base of the passage, or of each portion of the passage, may be tilted sideways so as to give a more easily regulated feed rate of the tablets.

The motion of the brush may be effected, for example, by means of an electric motor, or pneumatically. Since only the few tablets lying near to the brush are agitated,..

titre Patent Fig. 3 shows a view of the hopper of Fig. 1 in the direction of arrow B.

Fig. 4 shows a'view of the hopper of Fig. l in the direction of arrow A and with the brush raised to allow tablets to pass.

Figs. 5, 6 a'nd 7 show similar views of a hopper having a modified means of suspension of the brush and having a divided passage providing several streams of tablets.

Fig. 8 shows a divided passage in which the base of each portion can be independently adjusted for height.

Fig. 9 shows a'similar divided passage wherein the base of each portion is tilted sideways.

In the drawings, tablets 1 in a hopper 2 passes through a large outlet 3 into a short passage 4 the end of which is partially closed by a brush 5 suspended at a pivot 6 or through cranks 10 and i2 pivoted at 11 and 15. Brush 5 is driven by a motor 7 through crank S and link 9. As shown, the brush is movably mounted adjacent the outlet passage, the longitudinal extent of the brush being located in a plane which is at right angles to the plane of the base and extending transversely thereof. The brush is oscillated in this plane. The passage 4 may be divided by spacing plates 14 into separate portions 15 each of which has a level or transversely tilted spring leaf base 16 adjustable by a screw 17.

What I claim is:

-l. Tablet feed mechanism comprising a hopper having a base sloping relative to the horizontal, an outlet passage of limited depth leading from the lower end of said hopper, partition means defining a plurality of channels in said outlet passage, a brush mounted adjacent said outlet passage for oscillatory movement in a plane normal to the plane of said hopper base, the bristles of said brush extending toward but terminating short of the plane of said base, whereby said brush partially closes said outlet passage, means for oscillating said brush, and individual means in each of said outlet passage channels for adjusting the position of the channel bottom relative to the brush.

2. Tablet feed mechanism according to claim 1, wherein each channel bottom is transversely tilted. V

3. Tablet feed mechanism comprising a hopper having I a base sloping relative to the horizontal, an outlet passage of limited depth leading from the lower end of said hopper, a brush movably mounted adjacent said outlet passage, the longitudinal extent of said brush being located in a plane which is at right angles to the plane of the base and extending transversely thereof, the'bristles of said brush extending toward but terminating short of the plane of said base whereby said brush partially closes said outlet passage, and means for oscillating said brush'in said the longitudinal extent of said brush is' f in said outlet passage is partitioned into a plurality of channels.

-6. Tablet feed mechanism according to claim 3, includingrneans for adjusting the spacing betweensaid brush and the bottom of said outlet passage.

References Cited in the file of this patent UNITED STATES PATENTS.

327,011 Norton Sept. 29, 1885 699,828 Adolfsson .May 13,1902

' 734,631 Stubbs July 28, 1903 Y FOREIGN PATENTS 405,752 Great Britain Feb. 15, 1932 

